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BUCKEYE YARD AND GARDEN LINE 2008-13 6/26/08
From: Pam Bennett, Barb Bloetscher, Joe Boggs, Cindy Burskey, Jim Chatfield, Erik Draper, Dave Dyke, Gary Gao, David Goerig, Tim Malinich, Becky McCann, Amy Stone, and Curtis Young.
This is the 13th 2008 edition of the Buckeye Yard and Garden Line (BYGL). BYGL is developed from a Tuesday morning conference call of Extension Educators, Specialists, and other contributors in Ohio.
BYGL is available via email, contact Cheryl Fischnich [ This e-mail address is being protected from spambots. You need JavaScript enabled to view it ] to subscribe. Additional Factsheet information on any of these articles may be found through the OSU fact sheet database [ http://plantfacts.osu.edu/ ].
BYGL is a service of OSU Extension and is aided by major support from the ONLA (Ohio Nursery and Landscape Association) [ http://onla.org/ ] and [ http://buckeyegardening.com/ ] to the OSU Extension Nursery, Landscape and Turf Team (ENLTT). Any materials in this newsletter may be reproduced for educational purposes providing the source is credited.
BYGL is available online at: [ http://bygl.osu.edu ], a web site sponsored by the Ohio State University Department of Horticulture and Crop Sciences (HCS) as part of the "Horticulture in Virtual Perspective." The online version of BYGL has images associated with the articles and links to additional information.
Following are the participants in the June 24th conference call: Pam Bennett (Clark); Barb Bloetscher (Entomology/C. Wayne Ellett Plant and Pest Diagnostic Clinic (CWEPPDC)); Joe Boggs (Hamilton/Piketon); Cindy Burskey (Clermont); Jim Chatfield (Extension Specialist, Hort. & Crop Science); Erik Draper (Geauga) Gary Gao (Delaware); David Goerig (Mahoning); Becky McCann (Agricultural Business Enhancement Center (ABE Center)); Joe Rimelspach (Plant Pathology); Dave Shetlar (Entomology); Amy Stone (Lucas); Nancy Taylor (CWEPPDC); Curtis Young (Allen); and Randy Zondag (Lake). In This Issue: 1. WEATHERWATCH. 3. BUGBYTES: Odd Eriophyids; Lady Beetle Populations on the Rise; and Windshield Wipes [Japanese Beetles, Planthopper Nymphs, Assassin Bug Nymphs, Imported Cabbage Butterflies, Dogbane Leaf Beetle, Elm Flea Weevil]. 4. DISEASE DIGEST: Sampling for Vascular Wilt Diseases and Fireblight. 5. TURF TIPS: Thin Turf. 6. INDUSTRY INSIGHTS: Bagworm Alert. 7. COMING ATTRACTIONS: BYGL Live in Cincinnati and Northwest Ohio Green Industry Summer Session. 8. BYGLOSOPHY. 1. WEATHERWATCH. "Scattered" and "isolated" were the words of the week when it came to weather. Erik Draper reported a recent rainfall event that lasted just 20 minutes, but left 3/4" of rain behind in that short span of time. Randy Zondag reported that year-to-date precipitation totals in the northeast varied greatly from Avon, Madison, and Perry with ranges from 18-27". Joe Boggs reported "officially" that Cincinnati is nearly 9" above normal for the year, but also mentioned that 1" fell between June 4 and June 5, and since that event it has been dry with only 0.10" being reported. Storms continue to work their way across the state, soaking certain areas, and leaving others high and dry. Remember, there is nothing like putting a shovel into the ground to determine the soil moisture level. The following weather information summarizes data collected at various OARDC Weather Stations spanning the dates: June 1, 2008-June 25, 2008 with the exception of the soil temperatures which are readings from Wednesday, June 25 at 12:00 p.m. For a link to the OARDC Weather Stations, visit: [ http://www.oardc.ohio-state.edu/centernet/weather.htm ] 2. HORT SHORTS. A. GDD (GROWING DEGREE DAYS). GDD is a measure of the daily maximum and minimum temperature and directly relates to growth and development of plants and insects. The GDD of any zip code location in Ohio is estimated using the GDD of ten OARDC weather stations and available on the web at the site below. The range of GDD accumulations in Ohio from north to south is 880 to 1,206. Following is a report of GDD for several locations around Ohio as of June 24, 2008: Painesville, 880; Cleveland, 912; Toledo, 979; Canfield, 918; Lima, 985; Wooster, 933; Coshocton, 1,013; Columbus, 1,119; Springfield, 1,063; Dayton, 1,071; Cincinnati, 1,146; Ironton, 1,163; Portsmouth, 1,166; and Piketon, 1,206. To put these GDD accumulations into perspective, the following is an abbreviated listing of plant and insect species with their respective phenological event and average GDD accumulations at which these events occur. Due to variations in weather, temperature, humidity, etc., these events may occur a few days earlier or later than predicted by the average GDD. By looking at a city, town, or village near you from the above list, or visiting the above web site, you can see what could be taking place in the landscape around you. Mimosa webworm, egg hatch (first generation), 874; fuzzy deutzia, full bloom, 884; winged euonymus scale, egg hatch, 892; spruce budscale, egg hatch, 894; winterberry holly, full bloom, 897; panicled goldenraintree, first bloom, 924; June bride littleleaf linden, first bloom, 953; azalea bark scale, egg hatch, 957; Japanese beetle, adult emergence, 970; rosebay rhododendron, first bloom, 1,010; June bride littleleaf linden, full bloom, 1,115; bottlebrush buckeye, first bloom, 1,158; Ural falsespirea, first bloom, 1,170; and panicled goldenraintree, full bloom, 1,251. B. SPOTTED DYING TOMATO LEAVES. Pam Bennett reported anxious homeowners calling regarding spots on the lower leaves of tomatoes, which causes the leaf to turn yellow and then die. This is an accurate description of the symptoms of the fungal pathogen Septoria lycopersici, commonly known as SEPTORIA LEAF SPOT on tomato. This disease occurs at any stage of plant development from young seedlings to transplants; however, it is more typically observed on the older, lower leaves and stems, as fruits begin to set and develop. Spots may also appear on stems, calyces, and blossoms, but rarely on fruit. Tomato leaves heavily infected by Septoria turn yellow, dry up, and then drop off. This defoliation begins at bottom and progressively moves to the top of the plant. The fungal lesions first appear on the undersides of older leaves as small, water-soaked circular spots 1/16-1/8" in diameter. The centers of these spots are grey or tan, with a dark brown margin. With maturity, the spots may enlarge to about 1/4" across that eventually may even merge with each other. The key identification aspect to this disease is in the center of the spot one finds many dark brown to black, pimple-like structures called pycnidia or fruiting bodies of this fungus. The pycnidia are large enough to be easily seen with the eye or with the aid of a hand lens. To slow the spread of this disease use crop rotation, look for cultivars with good genetic resistance and practice good sanitation. If infected plants are found, rogue out and pick up the leaves. One of most effective ways to manage this disease is through the use of foliar fungicides, with repeated applications, to prevent infection of the plant leaves. * PERENNIAL PLANT OF THE WEEK. SHASTA DAISY (Leucanthemum x superbum) - These popular daisies are easy to grow, long blooming, readily available from local nurseries and are great cut flowers. The shasta daisy grows well in moist, well-drained soils and does not tolerate wet feet in the winter. There are many cultivars offering both single and double forms. Both types are best planted in partial shade but in cooler climates are full sun tolerant. Divide plants every 2-3 years to retain vigor and compactness. Taller growing selections should be pinched to keep them neat. To promote re-bloom plants should be deadheaded which may extend blooming time into early fall. Plants grow between 1-3' tall and approximately 2' wide; smaller cultivars have a round habit. * WOODY PLANT OF THE WEEK. GINKGO (Ginkgo biloba) - This medium to large stately tree is wonderful in the landscape, providing you have the male version! Female ginkgos are currently developing the lovely smelly fruits that overwhelm anyone who happens in the general vicinity of these trees in the fall. Look for male cultivars such as 'Autumn Gold', 'Lakeview', and 'Princeton Sentry'. Gingko trees grow to around 50-70' tall and are very adaptable to urban conditions and tough sites. They are used quite often as a street tree. Fall color on ginkgos is also quite lovely, though fleeting. The golden yellow leaves tend to drop all of sudden when temperatures change and wind kicks up. These trees have relatively few problems making them a great choice in the landscape. * ANNUAL PLANT OF THE WEEK. PORTULACA, MOSS ROSE (Portulaca grandiflora) - Not too many annuals tolerate the conditions that cause this annual to thrive! It likes full sun and well-drained soils and come August, when summer drought conditions are the worst, portulaca is at its best. Flowers bloom all summer and are pink, yellow, white, reddish, and purplish and can be double or single. The flowers open in the full sun and close at night and on cloudy days; however, some of the newer varieties remain open longer during the day and don't close up in cloudy weather. Portulaca grows around 6-8" tall and spreads up to 2'; it makes an excellent ground cover in the flower bed. Its thick leaves resemble a close relative, purslane (a difficult weed to eradicate in flower beds). * WEED OF THE WEEK. FIELD BINDWEED. Convolvulus arvensis, Field bindweed, a hardy perennial of the morning glory family, has been given many names including perennial morningglory, creeping jenny, bellbine, sheep-bine, and corn-bind. Field bindweed is primarily a weed of nurseries, agronomic crops, and fencerows that can be found throughout the United States, and is considered a noxious weed in 22 states. Drought tolerance is a characteristic of field bindweed and it grows in rich and sandy or gravelly soils. Field bindweed spreads by seed, rhizomes, root fragments, farm implements, infested soil adhering to the roots of nursery stock, root growth from infested areas, and by animals. Field bindweed is a long-lived perennial which produces a dense ground cover or climbing vine. The twining stems vary from 11/2-6' or more in length. The root system of field bindweed is extensive, with a twisting taproot reaching depths of 20' or more, and lateral roots extending 20-30'. Leaf size and shape are variable, but generally the leaves are 1/2-2" long, smooth and shaped like an arrowhead. The flowers are trumpet shaped, white to pink in color, and 1-11/2" wide. Field bindweed produces numerous seed in growing seasons. Its seed has a long dormancy and may last in soil for up to 60 years. Due to its extensive root system and seed production, field bindweed is one of the most persistent and difficult-to-control weeds. Control cannot be accomplished with a single treatment or in a single season. Effective control requires prevention of seed production, reduction of the root system by deep tillage, competition for light from other plants, and constant vigilance in removing top growth. Herbicides have been relatively effective for suppression of bindweed, but have not been very effective for eradication. If herbicides are used, supplement them with appropriate preventive and cultural controls. 3. BUGBYTES. A. ODD ERIOPHYIDS. Eriophyid mites (family Eriophyidae) are unique among other mites both in their anatomy and in the range of symptoms they produce on plants. First, they are very small. Most mites can be clearly seen with a 10x hand-lens. To clearly see eriophyid mites requires at least a 40x magnification. Second, most mites are round to oblong in their body shape and have four pairs of legs that extend laterally from the sides of their body. Eriophyid mites are cigar-shaped and they only have two pairs of legs that extend from the front of their body. No other mite has only two pairs of legs at any stage in their development. Eriophyids produce a wide range of symptoms on plants including rusty-red leaf and needle discoloration (rust mites), to fuzzy felt-like erineum patches on leaf surfaces, to raised "blisters" on leaf surfaces (blister mites), and to leaf and flower galls formed into a variety of shapes. Joe Boggs reported that he has received phone calls from landscapers who are observing many of these symptoms on trees and shrubs in southwest Ohio. The fuzzy, brightly colored leaf petiole galls on walnut produced by the eriophyid mite, Eriophyes caulis, are becoming very apparent in the southwest part of the state. The galls resemble pubescent pin cushions, and they first appear as greenish-white, irregular, solid, hard masses arising from the leaf petiole. As the galls mature, they become pink and finally deep red. Petioles may have a single gall, or several sometimes overlapping galls of varying lengths growing in a row. The galls often cause the petioles to become curled and stunted, and they may over-grow leaflets producing a gnarled, twisted mass of petioles and leaflets. The bizarre looking broccoli-like ash inflorescence (flower) galls caused by the eriophyid mite Eriophyes fraxinivorus are now gracing their namesake host. The galls consist of a profusion of clubby, distorted flower parts. They are sometimes described as looking like small witches' brooms growing just beneath this season's leaves. The similar looking catkin galls produced by Aculops tetanothrix are arising on willow. Of course, no list of eriophyid galls would be complete without mentioning the "bladder" and "spindle" galls that are now becoming very apparent. These include: the light-green to reddish-green, finger‑like spindle galls on the upper leaf surface of sugar maple, caused by the eriophyid Vasates aceriscrumena, and on the upper leaf surface of black cherry, caused by Phytoptus cerasicrumena (the "cherry-ophyid mite"); and the globose, pouch‑like "bladder galls" on the upper leaf surfaces of red and silver maples, caused by V. quadripedes. The craftsmanship of the eriophyid, A. toxicophagus, is just now becoming apparent on poison ivy, as irregular, wart‑like green to reddish-green galls on the upper leaf surface...looking much like the handiwork of poison ivy on the upper skin surface of gardeners. B. LADY BEETLE POPULATIONS ON THE RISE. Curtis Young and other BYGLers are reporting the presence of large numbers of lady beetle larvae on seemingly everything (e.g. tree leaves, flowers, shrubs, pools, toys, etc.). Many of these larvae are the offspring of the MULTICOLORED ASIAN LADY BEETLE (Harmonia axyridis). The larvae of the Asian lady beetle are identified by their black bodies marked with orange blotches and a series of spiked body protrusions. Apparently there are populations of prey species on many trees and shrubs that are not being detected by gardeners, homeowners or landscapers, but are being found by the lady beetles. If populations continue to build as they have to this point, it could be a banner year for the Asian lady beetle! Be prepared for potential problems in the fall with home invasions by the Asian lady beetle. C. WINDSHIELD WIPE. BYGLers also ran into a few other insects and mites this week including: * Dave Goerig, Dave Shetlar, Curtis Young, and Joe Boggs reported observing the first JAPANESE BEETLES (Popillia japonica) of the season in northeast, central, west, and southwest Ohio, respectively. The game is afoot! Dave Shetlar noted that these early-birds represent the tip of the iceberg with numbers gradually climbing as the season progresses. However, he also indicated that as with last season, population numbers will probably range widely throughout the state and he predicted beetle numbers in southern Ohio may be negatively affected by last season's drought. * Joe Boggs reported receiving phone calls from concerned homeowners concerning PLANTHOPPER NYMPHS on the stems of herbaceous perennials and low-growing woody ornamentals. Planthoppers are sucking insects, like aphids, and the nymphs of several species cloak themselves in a dense tangle of waxy, white "fluff." They also congregate in groups, or "colonies," and the collective profusion of flocculent material on plant stems draws attention to the insects. The nymphs also produce copious quantities of honeydew which may coat the plant and become colonized by black sooty molds. However, planthoppers seldom become more than a nuisance pest. If management is required, any insecticide labeled for use on the affected plant will be effective, or a course stream of water will also do the trick. * BYGLers reported that spider-like ASSASSIN BUG NYMPHS are roaming among the leaves of landscape plants in Ohio in search of an insect meal. With their long, spindly black legs, and their habit of holding their brightly colored abdomens in a vertical position, these Hemipterans (true bugs) are often mistaken for spiders. Assassin bug nymphs and adults wield long, piercing-sucking mouthparts which are used like soda straws to extract the essence-of-insect from their prey. The bugs belong to the family Reduviidae which has over 160 species that are found in North America. All are predators. The nymphs should be left alone for two reasons. First, they can use their sucking mouthparts to deliver a painful bite! Second, they are very important beneficial insects that kill insect pests. * Curtis Young reported receiving several calls in regard to white butterflies seemingly all over the landscape and hanging around field crops. The concern stems from people having just had a bad experience with armyworm caterpillars devouring wheat stands and turfgrass. Callers thought the armyworms and the butterflies might be connected. They are not! The adult of the armyworm is a buff colored moth that typically flies at night. The white butterflies that are in abundance in the landscape at the present time are IMPORTED CABBAGE BUTTERFLIES (Pieris rapae). Unless you are growing cabbage or some other host plant in the family Brassicaceae (a.k.a. Cruciferae) (e.g., cabbage, broccoli, cauliflower, turnip, rapeseed, mustard, radish, horseradish), you should have little concern for this delicate, flower-visiting butterfly. * Curtis Young also reported that dogbane (Apocynum cannabinum) is blooming in Allen County, one of the places that the imported cabbage butterfly (see above) was plentiful and is attracting several types of insects to it. One of the more striking of the visitors to the dogbane is the DOGBANE LEAF BEETLE (Chrysochus auratus). The dogbane leaf beetle adults congregate on the foliage of dogbane where they feed on the leaves, find mates and mate, and some lay small clutches of eggs under caps of excrement (others apparently drop to the ground and lay their eggs in the soil). This beetle is a sight to behold. It has a beautiful iridescent color to its body that appears to morph in color depending on how the light bounces off of it. * Curtis Young gave an update on the development of the ELM FLEA WEEVIL (Orchestes alni). The new adults have emerged and are feeding heavily on a number of elm species. The adult weevil is a skeletonizer. When it feeds, it chews off one epidermis and the center contents of the leaf and leaves one leaf epidermis in tact (this feeding could also be called window paning). The hole they produce on the leaf has an irregular circular shape. Numerous adults have been sited on some trees, lots of feeding scars are being produced giving leaves a lacy appearance and at least one report of homeowners being bitten by the little beasties when they were sitting under the infested trees. 4. DISEASE DIGEST. A. SAMPLING FOR VASCULAR WILT DISEASES. Verticillium wilt, Dutch elm disease, and oak wilt are all examples of vascular wilt diseases of trees that require sampling for verification. As Nancy Taylor of the OSU CWEPPD Clinic points out, though, sometimes she cannot culture out the causal fungus, even if is there, if she gets tiny 1/4" branch tips. The result is a false negative. Make sure to send samples 6-8" long with the thickness of your finger or bigger. There is also a better chance of getting true results if the plant tissue involved is actively wilting with leaves attached, rather than old dead twigs where the fungus is no longer living and therefore cannot be cultured. B. FIREBLIGHT. Bacterial pathogen; (Erwinia amylovora) or BROOD XIV PERIODICAL CICADA (Magicicada spp.)? Female periodical cicadas are producing fire blight look-a-like symptoms on ornamental pear in southern Ohio. The females use their spade-like ovipositors to insert eggs through the bark of twigs and into the white wood. The resulting damage splits the bark and white wood, leaving deep longitudinal furrows of ruptured tissue. The injury disrupts vascular flow and often causes the twig to die. The symptoms mimic those produced by fire blight with leaves turning brown to black and the tips of the twigs curving to produce "shepherds crooks." However, unlike fire blight, the slit-like oviposition wounds are clearly evident and the physical injury may cause the damaged twigs to break from the tree. Diagnosticians beware though, if you do not look closely, you may be fooled. 5. TURF TIPS. A. THIN TURF? People have inquired whether or not to fertilize their turfgrass now, considering the potential impending drought and high temperatures of summer. The answer really depends on the condition of the turfgrass and time when the lawn was last fertilized. If the lawn is thinning and weeds are encroaching, or if leaf diseases have been a problem in past summers, it would be wise to fertilize now to prevent weed seedlings from developing and curtail the outbreak of disease this season. The key to a successful fertilizer application is to use a granular form containing slow release nitrogen to feed the roots and prevent rapid, succulent leaf growth. Apply a granular fertilizer containing 30-50% slow release nitrogen to help the turfgrass replenish lost nutrients and commence root growth instead of shoot growth. Rust, some leaf spots, and other leaf diseases occur when drought stressed turfgrass can not grow quickly enough to outgrow the fungal advances; therefore a light application of fertilizer strengthens the resistance to theses diseases. Apply the fertilizer at least 24 hours before the next forecasted rainfall. Look at the list of ingredients under the heading of "Guaranteed Analysis". The percent of slow release (SR) fertilizers is mentioned under the list of ingredients, using the terms "slowly available" or "water insoluble" nitrogen. Sources of nitrogen which provide slow release nitrogen include sulfur coated urea, methylene urea, IBDU, natural products such as chicken manure or Milorganite, and synthetic fertilizers containing urea formaldehyde or poly coated urea. For lawns under a moderate maintenance program, apply at the rate of 3/4 lb N per 1000 square ft. Depending upon the turfgrass species mix and vigor of the turfgrass, this rate may vary, as tall fescue may not require as much nitrogen, while a newer cultivar of Kentucky bluegrass may require a pound of Nitrogen/1000 square feet, if the homeowner desires a higher quality lawn. 6. INDUSTRY INSIGHTS. A. BAGWORM ALERT! BYGLers have been closely following bagworm (Thyridopteryx ephemeraeformis) development throughout the spring. Eggs survived the winter well based on eggs observed in March 2008. Joe Boggs, Dave Shetlar and Curtis Young all reported egg hatch in Cincinnati, Columbus and Lima in the early part of June. Now, even though the caterpillars are still relatively small, their feeding damage is becoming evident on a number of their most susceptible hosts (i.e. arborvitae and spruce). Don't let the bagworm slip past undetected. Investigate suspicious looking plants, revisit plants that were infested in the past and re-evaluate plants that might have been diagnosed from afar as something else. For example, Joe Rimelspach reported what he thought was white pine weevil damage on white pines in his small Christmas tree planting was actually white pines infested with bagworm. What caused the short-term misdiagnosis was the fact that the bagworms had concentrated their feeding activity on the leader of the tree producing symptoms similar in appearance to white pine weevil activity. When looking for bagworm infestations, don't just look at the usual suspects. There are numerous trees and shrubs that will host bagworm populations that may not suffer greatly from the feeding activity of the bagworm, but may ultimately be the reservoir for reinfestation of neighboring evergreens. Some examples of these plants are maples, honeylocusts and crabapples. In landscapes where evergreens are regularly infested, these and other deciduous trees and shrubs should be inspected closely for infestations of bagworms. At this time the biological insecticide, Bacillus thuringiensis or Bt (e.g., Biobit, Dipel, Thuricide, Caterpillar Attack) can be quite effective against the bagworm. But don't wait too long for once the caterpillars reach 3/4" and bigger, the effectiveness of Bt declines rapidly. After this time, more traditional insecticides will be needed. However, don't wait till late in the growing season to manage the bagworm, because even the traditional insecticides lose their effectiveness against the large bagworms. Refer to OSU Extension Bulletin 504, "Insect and Mite Control on Woody Ornamentals and Herbaceous Perennials" for details on effective insecticides. 7. COMING ATTRACTIONS. 7. COMING ATTRACTIONS A. BYGLIVE! IN CINCINNATI. The fourth monthly BYGLive! Diagnostic Walk-About for 2008 will be held Monday, July 14, from 12:00 - 3:00 pm. at Glenwood Gardens (Hamilton County Park District), 10623 Springfield Pike, Woodlawn, 45215. This monthly hands-on training for Green Industry professionals focuses on diagnosing plant pest, disease, and physiological problems. ISA Certified Arborist CEU's will be available. Participants will meet in the parking lot furthest from the entrance to the Gardens. For more information, contact Joe Boggs at 513-946-8993. B. NORTHWEST OHIO GREEN INDUSTRY SUMMER SESSION. Remember to save the date for the 11th annual Northwest Ohio Green Industry Summer Session on August 6, 2008. The event will be held at Owens Community College. Bill Hendricks, from Klyn Nurseries, Inc., will speak on Tree Selections for Shade and Partial Shade and Top Woody Plant Selections. Additionally, this year's great line up of guest speakers includes: --Dr. Shetlar; Scales and Their Control Options, Pesticide Modes of Action 8. BYGLOSOPHY. "Look deep into nature, and then you will understand everything better" - Albert Einstein Where trade names are used, no discrimination is intended and no endorsement by Ohio State University Extension is implied. Although every attempt is made to produce information that is complete, timely, and accurate, the pesticide user bears responsibility of consulting the pesticide label and adhering to those directions. OSU Extension embraces human diversity and is committed to ensuring that all educational programs conducted by Ohio State University Extension are available to clientele on a nondiscriminatory basis without regard to race, color, age, gender identity, or expression, disability, religion, sexual orientation, national origin or veteran's status. Keith L. Smith, Associate Vice President for Ag. Adm. and Director, OSU Extension, TDD No. 800-589-8292 (Ohio only) or 614-292-1868. |
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| Last Updated ( Friday, 27 June 2008 13:13 ) |
